This policy brief presents new evidence on a policy relevant category of firms, fast growing mid-sized firms which have received limited attention in the academic and policy debate so far. Adopting a classification of firms often cited in the literature (Acs et al., 2008) that defines categories of firms using animal analogies (e.g. mice, gazelles, and elephants) we label these fast growing mid-sized firms as “Cheetah firms” (based on the RISIS-Cheetah dataset). The evidence presented here suggests that Cheetah firms can play a key role for economic growth and job creation, and thus they represent an important policy focus for the future. Specifically, the analysis shows that fast growing mid-sized firms are quite widespread but not evenly distributed both across European countries as well as within those countries. These firms present different characteristics compared to the other mid-sized firms, in terms of geographical localization and sectoral specialization. The analysis also suggests that that even though these firms manage to be fast growing, they find it hard to maintain such performance over time. Finally, several economic, demographic, and knowledge-related regional factors are associated to the emergence of clusters of fast growing mid-sized firms in European regions. The analysis of these firms in Europe provides some useful implications for policymakers. For instance, specific geographic areas seem to play a particularly important role, e.g. the Baltic and Eastern European countries, or other regions that are characterized by certain agglomeration dynamics and the presence of skilled human capital. Future developments of RISIS-Cheetah and a further integration within the RISIS data infrastructure will open new avenues for research and provide novel insights for evidence-based policy making.